Mycobacteria are significant human pathogens but are generally very slowly-growing organisms which may take weeks to identify even after being isolated in pure culture from clinical specimens. More rapid identification of such mycobacterial isolates would be clinically very useful, as the identification aids in determining the likelihood that the isolate is causing disease, helps determine whether isolation of the patient is necessary, and guides the choice of antibiotics. Several techniques for the rapid identification of these organisms have been reported, based on gas-liquid chromatography of cell wall extracts. We are attempting to adapt one of these procedures for use in our laboratory.